Cheapest priced copy (Dominaria): $0.35 at Card Kingdom, near mint, their price list as of .
Gaea's Protector 
Creature — Elemental Warrior · 4/2 · Common · The List · #DOM-162
This creature must be blocked if able.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Dominaria | 162 | Common | $0.35 | $0.49 |
| Jumpstart 2022 | 664 | Common | $0.35 | — |
| The List | DOM-162 | Common | $0.35 | — |
3 rulings from Wizards of the Coast
- 27 April 2018Only one creature is required to block Gaea’s Protector. Other creatures may also block it, and are free to block other creatures or not block at all.
- 27 April 2018If each creature the defending player controls can’t block for any reason (such as being tapped), then Gaea’s Protector isn’t blocked. If there’s a cost associated with blocking Gaea’s Protector, the defending player isn’t forced to pay that cost, so it doesn’t have to be blocked in that case either.
- 27 April 2018The defending player, not you, chooses which creature blocks Gaea’s Protector.